Device for introducing a predetermined dose of additive into a packaged liquid

ABSTRACT

The invention relates to an apparatus for introducing an additive material ( 131 ) in the form of a liquid or granulated solid into a liquid ( 40 ) stored in a first container ( 150 ). The additive component ( 131 ) is stored separately from the liquid ( 40 ) in a dip tube or conduit ( 130 ). The dip tube ( 130 ) is a resilient hollow tubular member and has a valve ( 300 ) at one end, adapted to open when the dip tube ( 130 ) is subject to internal pressure to allow the passage of said additive material ( 131 ) therethrough. The valve prevents the additive material ( 131 ) from leaking or dripping into the liquid ( 40 ) in the first container ( 150 ) when the dip tube and first container are at the same pressure, but which allows the passage of liquid or pourable solid additive from the dip tube ( 130 ) into the liquid ( 40 ) in the first container ( 150 ) when the dip tube is pressurised by introduction of propellant fluid ( 116, 516 ). A second valve ( 520 ) can be used to prevent the additive material ( 131 ) from leaking or dripping into a second container ( 150 ) which is the source of the pressurised propellant fluid ( 116, 516 ).

The invention relates to an apparatus for use with a container whichautomatically adds an additive in the form of a liquid or a pourablesolid to a liquid in the container on opening of the container. Inparticular the invention relates to a dip tube apparatus located withinthe container, the dip tube containing the additive and being closed atone end by a valve and connected at the other end to a pressure sourcewhich automatically pushes the additive through the valve into theliquid in the container on opening of the container.

In a wide number of applications, such as pharmaceuticals for both humanand animal use, agrochemicals and other more general applications it maybe necessary to release and mix a liquid catalyst or reagent into aliquid before the liquid may be used. In other applications, such as inthe beverage industry, it may be desirable to add a component to abeverage immediately before consumption of the beverage, for example toeffect a colour change, or to create a mixed beverage which has alimited storage life in the mixed state.

British Patent Application No 9823578 discloses an apparatus forintroducing a component into a first liquid, the apparatus comprising afirst container, such as a bottle, which holds the first liquid. Thecontainer has an opening closed by a releasable closure. A secondcontainer or tank containing pressurised propellant fluid is positionedin the neck of the first container, adjacent to the opening. A dip tubeor conduit is attached to the tank, and has a first end communicatingwith the tank and a second end extending down into the first liquid inthe first container. The dip tube contains an additive which is expelledfrom the dip tube into the first liquid by the entry of the propellantfluid from the tank into the conduit on release of the releasableclosure.

The preferred form of dip tube is a polypropylene tube of circularcross-section, typically having an internal diameter of 5.8 mm. Such atube has an internal capacity of 0.26 ml for each 10 mm length, so an 80mm long tube can hold approximately 2 ml of product. The tank typicallyhas a capacity of 2 ml, and contains pressurised propellant gas.

When the tank is of an impermeable material such as metal, then theheadspace required for the propellant gas is only a proportion of thetotal tank volume, leaving the remainder of the tank volume as well asthe tube volume available for product.

However when the tank is of a material such as plastic which exhibitslong term permeability, then the headspace required for the propellantgas must be maximised, and none of the tank volume is available forproduct. The product must all be held in the tube. If a large volume ofproduct is required it may be necessary to use larger diameter dip tubescapable of holding more product, and there is then a need for a valvearrangement at the lower end of the dip tube so that product does notdrip or seep into the first liquid in the first container. The use ofsmall diameter dip tubes such as capillary tubes avoids the need forvalves, but such small diameter dip tubes can only hold a small amountof product.

Similarly if the product must be completely isolated from the firstliquid in the first container there is a need for a valve arrangement atthe lower end of the dip tube so that the first liquid cannot enter thedip tube by capillary action.

There is therefore a need for a dip tube apparatus which has a dip tubecontaining the additive and closed at one en e, whereby the valve can bereadily opened when a pressure source pushes the additive through thevalve out of the dip tube.

According to the present invention there is provided an apparatus forintroducing an additive material into a first liquid, the apparatuscomprising:

-   -   a first container for holding the first liquid having an opening        closed by a releasable closure,    -   a second container positioned in the first container and        containing propellant fluid at a pressure greater than        atmospheric pressure, and    -   a tubular conduit having a first end communicating with the        second container and a second end communicating with the first        container;    -   wherein the conduit contains an additive material adapted to be        expelled from the conduit into the first liquid by the entry of        the propellant fluid into the conduit on release of the        releasable closure;    -   and wherein the conduit is provided with a first valve adjacent        to its second end, the first valve being adapted to prevent the        passage of said additive material into said liquid when the        pressure in said conduit is equal to the pressure in said        liquid, and the first valve being adapted to permit the passage        of said additive material into said liquid when the pressure in        said conduit is greater than the pressure in said liquid.

It is to be understood that the liquid may be a gel, a cream or agel-like material.

In one embodiment the first container may be a bottle having a neck. Thesecond container may be a tank or similar provided on the underside ofthe releasable closure. The conduit may extend below the surface of thefirst liquid in the bottle. Alternatively the conduit may extend to aposition close to the wall of the first container above the surface ofthe first liquid, to avoid foaming of the liquid and the creation ofpressure waves in the liquid.

In another embodiment the first container may be a can. The releasableclosure may be a ring pull closure or other known closure suitable foruse with a can. The can may have a cylindrical wall and two end walls,the closure being provided in one of the end walls. Preferably thesecond container is a tank attached to the inner surface of one of theend walls. Alternatively the second container may be freely suspended inthe first liquid in the can. Preferably the propellant fluid is gas.Preferably the second container is placed in the can prior to filling ofthe can with the first liquid under a pressure greater than atmosphericpressure.

A second valve may be provided in the conduit adjacent to the first endof the conduit, the second valve being adapted to prevent the passage ofsaid additive material into said second container, and the second valvebeing adapted to permit the passage of said propellant fluid into saidconduit when the pressure in said conduit is less than the pressure insaid second container.

In one embodiment the conduit comprises a hollow tubular member ofresilient plastics material, the first valve comprising a flattened endportion of the hollow tubular member, the flattened end portioncomprising two opposing walls held in contact with each other by theresilience of the plastics material and adapted to move out of contactwith each other when the hollow tubular member is subject to internalpressure to allow the passage of said additive material therethrough.

Preferably the flattened end portion is formed by applying heat to thetubular member. Preferably the heat is sufficient to cause plasticdeformation of the material, but not sufficient to cause melt bonding ofthe opposing walls.

The two opposing walls may be substantially planar. Alternatively thetwo opposing walls may be arcuate in transverse section, the outersurface of a first one of the opposing walls being in contact with theinner surface of the second one of the opposing walls.

The flattened end portion may comprise one or more transverse folds.Alternatively the flattened end portion may be curved or bent about atransverse axis. The flattened end portion may be rolled about atransverse axis.

Preferably the tubular member is of plastic, most preferably ofpolypropylene or HDPE. Preferably the tubular member is of circularcross-section.

In one embodiment the first valve comprises a plug means adapted to beejected from the conduit when the pressure in said conduit is greaterthan the pressure in said liquid.

The second valve may also comprise a plug means adapted to be propelledalong the conduit when the pressure in said conduit is greater than thepressure in said liquid, thereby causing the additive material to beejected from the conduit.

The first valve may be any suitable valve means, such as a poppet valveor similar. The second valve may be any suitable valve means, such as aone way valve.

The conduit may contain a number of additives arranged at differentpositions along the length of the conduit. The additives are preferablyliquid. However the additives may be provided in granule or powder form,preferably soluble. The additives may be colouring agents, flavouringagents, fragrances, pharmaceutical components, chemicals, nutrients,liquids containing gases in solution etc.

Examples of apparatus in accordance with the invention will now bedescribed with reference to the accompanying drawings, in which:—

FIGS. 1(a) to 1(e) are cross-sectional views of a first embodiment of anapparatus of the invention, in which a container containing propellantfluid is integrally formed in a bottle top, showing the top beforescrewing on, during screwing on, screwed on tight, during release andfully removed respectively;

FIG. 2 is a cross-sectional view of the embodiment of FIG. 1(a) to anenlarged scale;

FIG. 3 is a longitudinal cross-sectional view through a first embodimentof a dip tube and valve of the invention in its closed state;

FIG. 3 a is a section on line X—X through the valve of FIG. 3;

FIG. 4 is a longitudinal cross-sectional view through a secondembodiment of a dip tube and valve of the invention in its closed state;

FIG. 4 a is a section on line Y—Y through the valve of FIG. 4;

FIGS. 5 to 7 are longitudinal cross-sectional views through third,fourth and fifth embodiments respectively of a dip tube and valve of theinvention in its closed state; and

FIG. 8 is a cross-sectional view of a second embodiment of an apparatusof the invention, in which the first container holding the liquid is acan.

FIGS. 1(a) to 1(e) show an apparatus for automatically dispensing aproduct from a dip tube to a bottle or first container by means ofpressurised propellant stored in a tank or second container when the topis removed from the bottle. The tank or second container is integrallyformed with a screw top which is then screwed onto the bottle or firstcontainer, in the neck of which is secured an insert which has arupturing spike and a dip tube.

FIG. 1(a) shows a bottle 150 having an insert 100 secured within theneck 160 of the bottle, shown in more detail in FIG. 2. The screw cap152 is shown separately, before closure of the bottle 150. The cap 152has an internal thread to mate with the external thread on the neck 160of the bottle. The cap has an integrally moulded cylindrical portionwhich forms an inner container 111, which is closed at the upper end bya convex portion 112 of the cap 152, so as to resist internal pressurein the inner container, and is open at the lower end 113. Acircumferential groove 114 is provided externally at the lower end 113of the inner container 111.

A plastic ferrule 170 comprises an inner cylindrical wall 172 forming achamber which is open at its lower end and closed by a foil seal ormembrane 180 at its upper end. The inner cylindrical wall 172 isconnected and sealed at its upper end to an outer cylindrical wall 174,whose outside diameter is selected to fit tightly within the insidediameter of the inner container 111. At the lower end of the outercylindrical wall 174 is provided a return flange 176 which has acircumferential rib 178 adapted to cooperate with the groove 114 on theoutside wall of the inner container 11. The inner wall 172 has upper andlower sealing ribs 182, 183 which are adapted to provide a pressureresistant seal against the outer surface of the rupturing member 104.

The ferrule 170 is secured by a snap fit to the lower end 113 of theinner container 111, to provide a pressure resistant closure to thecontainer. The inner container is filled with liquid 115 and pressurisedgas 116 in a conventional fashion, so that the inner container is underinternal pressure, causing the foil seal 180 to bow outwards.

An insert 100 is secured by any suitable means within the neck 160 ofthe bottle 150. The insert 100 comprises a substantially cylindricalhousing 101 open at the upper end and having a number of legs 190projecting from the lower end. The housing is provided with detentmembers 191 which engage with the inside of the neck 160 of the bottle,so that the insert 100 cannot be readily removed. The upper end of thehousing has a lip 102 which is adapted to engage with a recess 103 inthe neck 160 of the bottle, to prevent the insert from being pushed downinside the neck.

The legs 190 are connected at their lower end to a hollow spike member104, which has a small diameter bore portion 105 at its upper end and alarge diameter bore portion 106 at its lower end. Between the legs areapertures which allow the passage of liquid between the spike member 104and the side of the bottle when the liquid is poured from the bottle.The number of legs and intervening apertures may be two, three, four ormore as appropriate.

Within the wall of the small diameter bore portion 105 are provided anumber of radial passages 108 which communicate with the hollow interiorof the spike 104 and the interior of the housing 101. Extending from thebottom of the hollow rupturing member 104 is a dip tube or conduit 130,surrounded by a plastic or sprung steel cone washer 109 which is securedto the rupturing member 104 and serves as a one-way retaining member toallow the conduit 130 to be inserted up into the large diameter bore 106but to restrain it from being removed in a downwards direction. Thelarge diameter bore portion 106 has an internal diameter equal to theexternal diameter of the dip tube 130. The step between the large andsmall diameter bore portions 105, 106 prevents the dip tube 30 extendinginto the small diameter bore portion 10S and blocking the radialapertures 108.

In use, the inner container 111 is filled with a liquid 115 and apressurised gas 116 by means of conventional technology used to fillpressurised dispenser packs, commonly known as aerosol containers.Alternatively the inner container 111 may be filled solely withpressurised gas 116, omitting the liquid 115.

FIG. 1(b) shows the cap 152 while it is being screwed on to the neck160. On application of the closure or cap 152 to the bottle 150, theinner container 111 is moved downwards and the spike 104 enters thespace formed by the inner cylindrical wall 172 of the ferrule 170.

When the closure 152 is fully screwed tight on to the bottle 150, theinner container ill moves to the position shown in FIG. 1(c), in whichthe seal member 154 inside the cap 152 seals tightly against the top 156of the bottle neck 160. When this happens, the spike 104 bursts therupturable membrane 180 and the member hollow spike extends into theinner container 111. In this position the liquid 115 and gas 116 areprevented from escaping from the inner container 111 by the ferrule 170and spike member 104 which seal against each other to prevent release ofthe liquid 115 and gas 116 from the container 111. The upper sealing rib182 and lower sealing rib 183 formed inside the inner cylindrical wall172 of the ferrule 170 both seal against the outer surface of the spikemember 104.

The inner container 111 remains in the position shown in FIG. 1(c) untila user releases the closure 152 from the bottle 150. When this occurs,the inner container 111 moves to the position shown in FIG. 1(d). Inthis position the upper sealing rib 182 becomes unsealed from the spikemember 104, but the lower sealing rib 183 remains in sealing contactwith the outer surface of the spike member, below the apertures 108.This leaves an escape passage for the compressed liquid 115 (or gas116), which is forced out of the container 111 by the pressurised gas116 in the direction of arrows 184, 185, 186, between the spike member104 and ferrule 170, through the radial passages 108 and into the diptube 130. The liquid 115 or gas 116 then passes through the dip tube130, expelling the concentrate or additive material 131 from the diptube 130 through the valve 300, shown schematically in FIGS. 1 and 2,into the liquid or other substance contained in the bottle 150. Onremoval of the closure 152, the inner container 111 and ruptured ferrule170 are removed from the bottle 150 together, as shown in FIG. 1(e),leaving the insert 100 and dip tube 130 in the bottle. The insert doesnot impede pouring of the liquid in the bottle, which can flow betweenthe support legs 190 of the insert 100.

The dip tubes 130, typically thin-walled polypropylene tubes such asused in the manufacture of drinking straws or similar, may be ofdifferent diameter or length and may contain different predetermineddoses of additives. However the dip tubes may be larger diameter plastictubes, holding for example 10 ml of additive material The tank 111 maybe only 2.5 ml in volume, if pressurised to four or five timesatmospheric pressure, so that on release of the closure 152 thepropellant 116 expands to four or five times its volume, thereforeexpelling all the additive product 131 from the dip tube 130.

FIGS. 3 to 7 show five different embodiments of the valve 300 providedat the lower end of the dip tube 130. In all cases the material 131 isheld in the dip tube by the flattened end portion of the dip tube, andcannot exit from the dip tube until the dip tube is pressurised, causingthe flattened end portion to open. The flattened end portion is formedby applying heat to the end of the dip tube 130. The heat is sufficientto cause plastic deformation of the material, but not sufficient tocause melt bonding of the opposing walls.

In the first embodiment of FIG. 3 the lower end of the dip tube 130 isprovided with a flattened, duck bill shaped end portion 201. Thisarrangement requires a significant internal pressure before the valvewill open, since the natural spring action of the inner wall 202 meansit must “pop” open away from outer wall 203.

In the second embodiment of FIG. 4 the lower end of the dip tube 130 isprovided with a simple, planar, flattened end portion 211. The heatingaction means that the two walls 212, 213 are in equilibrium in theclosed position.

In the third embodiment of FIG. 5 the flattened end portion 221 isfolded back on itself, to provide a more secure closure. A high internalpresuure is required, first to expand the upper portion 222 of theflattened end portion 221, and then to cause the fold 223 to straightenout, before the lower portion 224 can expand. The heating action meansthat the fold 223 is in equilibrium in the folded position.

The fourth embodiment of FIG. 6 is similar to that shown in FIG. 5,except that there are three folds 232 provided in the flattened endportion 231. Two or four or more folds may be provided if required.

In the fifth embodiment of FIG. 7 the flattened end portion 241 isrolled in a coil, which unrolls upon the application of internalpressure to the dip tube 130.

FIG. 8 shows a partial view of a beverage can 500 having a cylindricalside wall 502, a lower end wall 504 and an upper end wall (not shown)which is provided with a conventional ring pull closure (not shown).Inside the can 500 a substantially impervious propellant container 510,which may be of metal or plastic, is secured to the inner surface of theend wall 504. The propellant container 510 has a single large opening512 at its upper side, as well as a very small diameter bleed hole 518at its lower side, typically 0.3 mm in diameter or less. Extending fromthe opening 512 is a dip tube or conduit 130, surrounded by a plastic orsprung steel cone washer 514 which is secured to the rupturing membercontainer 510 and serves as a one-way retaining member to allow theconduit 130 to be inserted into the opening 512 but to restrain it frombeing removed therefrom. Other methods of securing the dip tube 130 tothe propellant container 510 may be used, in place of washer 514.

After the can 500 is filled with the beverage 540, liquid nitrogen isadded to the beverage 540, the can 500 is sealed and inverted. Theheadspace in the can reaches an equilibrium pressure P_(f) significantlyhigher than atmospheric pressure. This is a known technique with“widget” technology. Before filling the can with beverage, theunpressurised propellant container 510 and the dip tube, which containsadditive product 131, are both attached to the bottom surface 504 of thecan. The nitrogen gas in the headspace slowly enters the propellantcontainer 510 through the bleed hole 518 over a time of several minutes,until the interior of the propellant container reaches the higherpressure, so that the insides of the can and the container 510 remain atthe higher equilibrium pressure P_(f). The can may then be placed thecorrect way up again. When the can is opened by releasing the ring pullclosure, the pressure of the beverage in the can reverts to atmosphericpressure P_(a). As a result of the pressure difference between theinterior of the propellant container 510 and the interior of the can500, propellant 516, in this case nitrogen gas, at pressure P_(f) isforced through the opening 512 and along the dip tube 130, forcing openthe valve 300 and expelling the concentrate or additive material 131from the dip tube 130 through the valve 300, shown schematically in FIG.8, into the beverage 540 or other substance contained in the can 500.The path through the dip tube 130 represents a path of less resistancefor the propellant 516 than through the bleed hole 518, because of thesmall size of the bleed hole 518.

To prevent additive 131 from passing into the propellant container 510,a second valve (not shown) may be provided in the portion 310 of the diptube 130 adjacent to the opening 512. This second valve may be any formof one way valve. Alternatively a readily rupturable membrane (notshown) may be provided at the opening 512 of the propellant container,which ruptures as soon as there is a greater pressure in the container510 than outside. Alternatively a plug 520, shown in dotted outline inFIG. 8, such as a ball of glycerine or some inert gel-like substance,may be inserted in the portion 310 of the dip tube 130 to preventadditive 131 from passing into the propellant container 510. The plug520 is driven up through the dip tube under pressure from the propellant516 on opening of the can 500.

It is envisaged that the dip tube valve arrangement may find otherapplications, and the invention is not be limited to use of the valvewith the pressurised dispensing devices as shown in FIGS. 1(a) to 1(e)and FIG. 8.

The invention can be used with fragrances, flavouring, pharmaceuticals(particularly suitable because of the accurate dosage obtainable),chemicals, vitamins etc. The tubes can be filled precisely at adifferent location and then inserted into the housing at the point offilling the bottles. Compressed air or other gas is particularlysuitable as a propellant for powdered or granulated solids, so thatliquid does not cause the solids to adhere to the side of the dip tube.

The dip tube valve of the invention is an inexpensive valve arrangementwhich prevents the product in a dip tube from leaking or dripping intothe first liquid in the first container when the dip tube and firstcontainer are at the same pressure, but which allows the passage ofliquid or pourable solid product from the dip tube into the first liquidin the first container when the dip tube is pressurised by introductionof the propellant fluid.

Modifications and improvements may be incorporated without departingfrom the scope of the invention.

1. An apparatus for introducing an additive material into a firstliquid, the apparatus comprising: a first container for holding thefirst liquid having an opening closed by a releasable closure, a secondcontainer positioned in the first container and containing propellantfluid at a pressure greater than atmospheric pressure, and a tubularconduit having a first end communicating with the second container and asecond end communicating with the first container; wherein the conduitcontains an additive material adapted to be expelled from the conduitinto the first liquid by the entry of the propellant fluid into theconduit on release of the releasable closure; wherein the conduit isprovided with a first valve adjacent to its second end, the first valvebeing adapted to prevent the passage of said additive material into saidfirst liquid when the pressure in said conduit is equal to the pressurein said first liquid, and the first valve being adapted to permit thepassage of said additive material into said first liquid when thepressure in said conduit is greater than the pressure in said firstliquid; and wherein the second container has a bleed hole incommunication with the first container adapted to permit the pressure inthe second container and the first container to reach equilibrium over aperiod of time.
 2. An apparatus according to claim 1, wherein the liquidis a gel or gel-like material.
 3. An apparatus according to claim 1,wherein the first container is a can and the releasable closure is aring pull closure.
 4. An apparatus according to claim 3, wherein the canhas a cylindrical wall and two end walls, the second container beingattached to the inner surface of one of the end walls.
 5. An apparatusaccording to claim 1, wherein the conduit comprises a hollow tubularmember of resilient plastics material, the first valve comprising aflattened end portion of the hollow tubular member, the flattened endportion comprising two opposing walls held in contact with each other bythe resilience of the plastics material and adapted to move out ofcontact with each other when the hollow tubular member is subject tointernal pressure to allow the passage of said additive materialtherethrough.
 6. An apparatus according to claim 5, wherein theflattened end portion is formed by applying heat to the tubular member.7. An apparatus according to claim 5, wherein the two opposing walls aresubstantially planar.
 8. An apparatus according to claim 5, wherein thetwo opposing walls are arcuate in transverse section, the outer surfaceof a first one of the opposing walls being in contact with the innersurface of the second one of the opposing walls.
 9. An apparatusaccording to claim 5, wherein the flattened end portion comprises one ormore transverse folds.
 10. An apparatus according to claim 5, whereinthe flattened end portion is curved, bent or rolled about a transverseaxis.
 11. An apparatus according to claim 1 wherein the first valvecomprises a plug means adapted to be ejected from the conduit when thepressure in said conduit is greater than the pressure in said firstliquid.
 12. An apparatus according to claim 1 wherein the first valvecomprises a poppet valve.